New insights into the cytotoxic mechanism of marine-fungus-derived citrinin in three-dimensional Hepa1-6 cell model

Although recent studies have demonstrated that Marine-fungus-derived citrinin (MFDC) has a significant cytotoxic effect in traditional two-dimensional (2D) monolayer cell culture and animal models, its precise cytotoxic mechanism, particularly in a three-dimensional (3D) cell culture model remains unclear. In this study, a 3D Hepa1-6 cell model based on Matrigel was used to investigate the potential cytotoxic mechanism of MFDC (0-100 μg/mL). The results revealed that, after treatment of 60-100 μg/mL MFDC, the increases of reactive oxygen species (ROS), lactate dehydrogenase (LDH), aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in 2D cell model were more significant than those in 3D cell model. In addition, the metabolomic results revealed that the significantly altered metabolic pathways were pyrimidine metabolism and vitamin B6 metabolism, which might be related to the interference of MFDC in the pyrimidine synthesis pathway, as well as the upregulation of pyridoxine 5'phosphate oxidase and pyridoxal kinase activities. This study was the first to compare the cytotoxicology of 2D and Matrigel-based 3D cell models after MFDC induction, and to detect differences in cell metabolites after MFDC induction in 3D cell models, providing a new scientific basis for the use of a 3D cell model and a novel research idea for the cellular damage caused by MFDC.

Molecular docking and antitumor evaluation of liposomal nanoformulations containing citrinin

The search for novel drugs based on natural products combined with nanosystems has circumvented limitations and barriers in cancer treatment. Citrinin (CIT), a mycotoxin produced by the fungus Penicillium citrinum, has demonstrated cytotoxicity in tumor models and may represent a promising antitumor agent. In this study, we aimed to evaluate the cytotoxic, genotoxic, and mutagenic effects of CIT and a liposomal nanoformulation containing CIT (LP-CIT) in MCF7 breast cancer cells. The selected concentrations were based on preliminary range-finding assays to determine optimal cytotoxicity while maintaining assay reliability. The toxicogenetic evaluations and mechanistic analyses included MTT, trypan blue exclusion, cytokinesis-block micronucleus (CBMN) assays, fluorescence confocal microscopy, and molecular docking studies. CIT and LP-CIT showed cytotoxicity in MCF7 cells, with LP-CIT presenting significantly reduced IC50 values (0.90 µg/mL) compared to free CIT (18.25 µg/mL), possibly due to enhanced cellular uptake via liposomal delivery. Confocal microscopy revealed that both treatments significantly reduced cell viability and increased apoptosis. In addition, CBMN assays demonstrated equivalent cytostatic and mutagenic effects for CIT and LP-CIT. Docking analysis suggested interactions of CIT with mitogen-activated protein kinases, including MAPK-1, B-Raf, and ERK, indicating possible activation of apoptotic pathways via ERK1/2. In conclusion, CIT and its liposomal nanoformulation (LP-CIT) exhibited cytotoxic and mutagenic activity in human breast tumor cells by inducing apoptosis and modulating oncogenic pathways.

Citrinin-Induced Cellular Damage: Insights from SH-SY5Y Cell Line Studies

Citrinin (CIT), a mycotoxin commonly found in cereals, is produced by fungi from the Aspergillus, Penicillium, and Monascus genera. While its nephrotoxic effects are well studied, its impact on neurons is less understood. This study investigates CIT-induced toxicity in human neuroblastoma cells (SH-SY5Y). The IC50 values for cells treated with CIT were 77.1 μM at 24 h and 74.7 μM at 48 h using MTT assay, and 101.0 μM at 24 h and 54.7 μM at 48 h using neutral red assay. CIT exposure caused G2/M phase arrest, with cells in this phase increasing from 11.83% (control) to 33.10% at 50 μM CIT. At 50 μM, the percentage of cells in the S phase also increased, which may suggest that cellular stress pathways were activated. Moreover, an increase in late apoptosis process was noted in cells exposed to CIT for 24 h, particularly at the highest concentrations (38.75 and 50 µM). Western blot analysis confirmed a rapid change in the anti-apoptotic protein Bcl-2, but no significant changes in Bax. In conclusion, CIT induces apoptosis and cell cycle arrest in SH-SY5Y cells. However, further transcriptomic studies in specific proteins involved in different pathways described in this work are needed to gain a comprehensive understanding of the specific mechanisms underlying CIT's toxicity in SH-SY5Y cells.

Citrinin disrupts microtubule assembly in cardiac cells: Impact on mitochondrial organization and function

Citrinin (CTN) is a mycotoxin commonly present in various foods and feeds worldwide, as well as dietary supplements in Asian countries, but the risks and cellular mechanisms associated with its cardiotoxicity remains unclear. In this study, RNA-seq analysis of CTN-treated H9c2 cardiac cells demonstrated significant perturbations in pathways related to microtubule cytoskeleton and mitochondrial network organization. CTN disrupted microtubule polymerization and downregulated mRNA levels of microtubule-assembling genes, Map2 and Tpx2, in H9c2 cardiac cells. Additionally, CTN interfered with the distribution of mitochondrial network along the microtubules, leading to the accumulation of dysfunctional mitochondria characterized by elevated superoxide levels and reduced membrane potential. This disruption also caused the buildup of lysosomes and ubiquitinated proteins, which hindered waste clearance in microtubule-disassembled H9c2 cells. Molecular docking analysis indicated that CTN could bind to the colchicine binding site on β-tubulin, thereby mimicking the microtubule-disrupting effect of colchicine. This study provides morphological, transcriptomic, and mechanistic evidence to elucidate the cardiotoxic mechanisms of CTN, which involve the dysregulated microtubule network, subsequent mitochondrial mislocalization, and impaired proteolysis of damaged proteins/organelles in cardiac cells. Our findings may enhance the fundamental understanding and facilitate future risk assessment of CTN.

Citrinin Provoke DNA Damage and Cell-Cycle Arrest Related to Chk2 and FANCD2 Checkpoint Proteins in Hepatocellular and Adenocarcinoma Cell Lines

Citrinin (CIT), a polyketide mycotoxin produced by Penicillium, Aspergillus, and Monascus species, is a contaminant that has been found in various food commodities and was also detected in house dust. Several studies showed that CIT can impair the kidney, liver, heart, immune, and reproductive systems in animals by mechanisms so far not completely elucidated. In this study, we investigated the CIT mode of action on two human tumor cell lines, HepG2 (hepatocellular carcinoma) and A549 (lung adenocarcinoma). Cytotoxic concentrations were determined using an MTT proliferation assay. The genotoxic effect of sub-IC50 concentrations was investigated using the alkaline comet assay and the impact on the cell cycle using flow cytometry. Additionally, the CIT effect on the total amount and phosphorylation of two cell-cycle-checkpoint proteins, the serine/threonine kinase Chk2 and Fanconi anemia (FA) group D2 (FANCD2), was determined by the cell-based ELISA. The data were analyzed using GraphPad Prism statistical software. The CIT IC50 for HepG2 was 107.3 µM, and for A549, it was >250 µM. The results showed that sensitivity to CIT is cell-type dependent and that CIT in sub-IC50 and near IC50 induces significant DNA damage and cell-cycle arrest in the G2/M phase, which is related to the increase in total and phosphorylated Chk2 and FANCD2 checkpoint proteins in HepG2 and A549 cells.

Mechanisms underlying citrinin-induced toxicity via oxidative stress and apoptosis-mediated by mitochondrial-dependent pathway in SH-SY5Y cells

Citrinin (CIT) is a mycotoxin produced as a secondary product by the genera Aspergillus, Penicillium, Monascus, and other strains. CIT has the potential for contaminating animal feed and human food such as maize, wheat, rye, barley, oats, rice, cheese, and sake. Although CIT is primarily known as a nephrotoxic mycotoxin, it also affects other organs, including the liver and bone marrow, and its mechanisms of toxicity have not been clearly elucidated. There is a further lack of studies investigating the potential for CIT-induced neurotoxicity and its mechanisms. In the current study, SH-SY5Y human neuroblastoma cell line was treated with CIT for 24 h to evaluate various toxicological endpoints, such as reactive oxygen species (ROS) production and apoptosis induction. Results indicate that CIT has an IC50 value of 250.90 μM and cell proliferation decreased significantly at 50 and 100 μM CIT concentrations. These same concentrations also caused elevated ROS production (≥34.76%), apoptosis (≥9.43-fold) and calcium ion mobilization (≥36.52%) in the cells. Results show a significant decrease in the mitochondrial membrane potential (≥86.8%). We also found that CIT significantly upregulated the expression of some genes related to oxidative stress and apoptosis, while downregulating others. These results suggest that apoptosis and oxidative stress may be involved in the mechanisms underlying CIT-induced neurotoxicity.

Citrinin as a potential anti-cancer therapy: A comprehensive review

Citrinin (CIT) is a polyketide-derived mycotoxin, which is produced by many fungal strains belonging to the gerena Monascus, Aspergillus, and Penicillium. It has been postulated that mycotoxins have several toxic mechanisms and are potentially used as antineoplastic agents. Therefore, the present study carried out a systematic review, including articles from 1978 to 2022, by collecting evidence in experimental studies of CIT antiplorifactive activity in cancer. The Data indicate that CIT intervenes in important mediators and cell signaling pathways, including MAPKs, ERK1/2, JNK, Bcl-2, BAX, caspases 3,6,7 and 9, p53, p21, PARP cleavage, MDA, reactive oxygen species (ROS) and antioxidant defenses (SOD, CAT, GST and GPX). These factors demonstrate the potential antitumor drug CIT in inducing cell death, reducing DNA repair capacity and inducing cytotoxic and genotoxic effects in cancer cells.

Chemical Compositions and Experimental and Computational Modeling of the Anticancer Effects of Cnidocyte Venoms of Jellyfish Cassiopea andromeda and Catostylus mosaicus on Human Adenocarcinoma A549 Cells

Nowadays, major attention is being paid to curing different types of cancers and is focused on natural resources, including oceans and marine environments. Jellyfish are marine animals with the ability to utilize their venom in order to both feed and defend. Prior studies have displayed the anticancer capabilities of various jellyfish. Hence, we examined the anticancer features of the venom of Cassiopea andromeda and Catostylus mosaicus in an in vitro situation against the human pulmonary adenocarcinoma (A549) cancer cell line. The MTT assay demonstrated that both mentioned venoms have anti-tumoral ability in a dose-dependent manner. Western blot analysis proved that both venoms can increase some pro-apoptotic factors and reduce some anti-apoptotic molecules that lead to the inducing of apoptosis in A549 cells. GC/MS analysis demonstrated some compounds with biological effects, including anti-inflammatory, antioxidant and anti-cancer activities. Molecular docking and molecular dynamic showed the best position of each biologically active component on the different death receptors, which are involved in the process of apoptosis in A549 cells. Ultimately, this study has proven that both venoms of C. andromeda and C. mosaicus have the capability to suppress A549 cells in an in vitro condition and they might be utilized in order to design and develop brand new anticancer agents in the near future.

Detoxication of Citrinin with Kojic Acid by the Formation of the Citrinin-Kojic Acid Adduct, and the Enhancement of Kojic Acid Production by Citrinin via Oxidative Stress in Aspergillus parasiticus

Our previous work showed that citrinin (CTN) produced bay Penicillium citrinum inhibited the production of aflatoxin by Aspergillus parasiticus. We also reported that CTN was non-enzymatically converted to a novel CTN-KA adduct with kojic acid (KA) in aqueous condition. We herein observed that unlike CTN, the CTN-KA adduct does not show antimicrobial activity against Escherichia coli or Bacillus subtilis or any cytotoxic effect on HeLa cells, suggesting that CTN was detoxified by KA by the formation of the CTN-KA adduct. To examine the function of KA production by fungi, we isolated A. parasiticus mutants with impaired KA production. When the mutants were incubated in either liquid or agar medium supplemented with CTN, they were more susceptible to CTN than the wild KA-producing strain. The same results were obtained when we used the A. oryzae KA-producing strain RIB40 and KA-non-producing strains. When KA was added to the CTN-containing agar medium, the inhibition of growth by CTN was remarkably mitigated, suggesting that the production of KA protected the fungal growth from CTN's toxicity. We also observed that CTN enhanced the production of KA by A. parasiticus as well as A. oryzae strains. Reverse transcription-PCR showed that CTN enhanced the expression of KA biosynthetic genes (kojA, kojR, and kojT) of A. parasiticus. However, the enhancement of KA production with CTN was repressed by the addition of α-tocopherol or butylated hydroxy anisole, suggesting that KA production is enhanced by oxidative stress via the formation of reactive oxygen species caused by CTN. In contrast, α-tocopherol did not affect inhibition of AF production as well as fungal growth by CTN, suggesting that the regulation of these inhibitions with CTN might be different from that of KA production. We propose a regulation scheme of CTN for each of KA production, AF production, and fungal growth in A. parasiticus.

Inhibition of Aflatoxin Production by Citrinin and Non-Enzymatic Formation of a Novel Citrinin-Kojic Acid Adduct

Screening for microorganisms that inhibit aflatoxin production from environments showed that Penicillium citrinum inhibited aflatoxin production by Aspergillus parasiticus. The inhibitory substance in the culture medium of P. citrinum was confirmed to be citrinin (CTN). RT-PCR analyses showed that CTN did not inhibit expressions of aflatoxin biosynthetic genes (aflR, pksL1, and fas-1) of A. parasiticus, whereas feeding experiments using A. parasiticus showed that CTN inhibited the in vivo conversion of dihydrosterigmatocystin to AFB₂·AFG₂. These results suggest that CTN inhibits a certain post-transcriptional step in aflatoxin biosynthesis. CTN in the culture medium of A. parasiticus was found to be decreased or lost with time, suggesting that a certain metabolite produced by A. parasiticus is the cause of the CTN decrease; we then purified, characterized, and then analyzed the substance. Physico-chemical analyses confirmed that the metabolite causing a decrease in CTN fluorescence was kojic acid (KA) and the resulting product was identified as a novel substance: (1R,3S,4R)-3,4-dihydro-6,8-dihydroxy-1-(3-hydroxy-6-(hydroxymethyl)-4-oxo-4H-pyran-2-yl)-3,4,5-trimethyl-1H-isochromene-7-carboxylic acid, which was named "CTN-KA adduct". Our examination of the metabolites' toxicities revealed that unlike CTN, the CTN-KA adduct did not inhibit aflatoxin production by A. parasiticus. These results indicate that CTN's toxicity was alleviated with KA by converting CTN to the CTN-KA adduct.

Neurotoxicity of mycotoxin citrinin: Novel evidence in developing zebrafish and underlying mechanisms in human neuron cells

Citrinin (CTN) is a mycotoxin that is found as a contaminant in various types of food/feed grains and fermented food supplements. Previous studies have already established the nephrotoxicity and hepatotoxicity of CTN, but the neurotoxicity of CTN has not been clearly examined. In this study, CTN at 2-20 μM was first found to interfere with the neural ganglia formation and locomotive behavior of embryonic zebrafish, a vertebrate animal model, at 24 hpf and 6 dpf, respectively. Further exposure of human neuroblastoma SH-SY5Y cells to 10 and 20 μM CTN for 72 h indicated that pathways responsible for neuron differentiation and projection guidance were down-regulated while oxidative stress and electron transport chain pathways were up-regulated based on the enrichment results of GSEA in the transcriptomic profiling. PCR analysis verified that CTN significantly down-regulated the expression of marker genes involved in neuron differentiation and synaptic signaling. CTN at the doses impairing cellular neurite outgrowth did not trigger mitochondrial oxidative stress and dysfunction. The neurotoxic mechanisms of CTN provide new information that is valuable in the assessment of CTN-related health risk for the general public.

Hesperidin Exhibits Protective Effects against PM2.5-Mediated Mitochondrial Damage, Cell Cycle Arrest, and Cellular Senescence in Human HaCaT Keratinocytes

Particulate matter 2.5 (PM_2.5) exposure can trigger adverse health outcomes in the human skin, such as skin aging, wrinkles, pigment spots, and atopic dermatitis. PM_2.5 is associated with mitochondrial damage and the generation of reactive oxygen species (ROS). Hesperidin is a bioflavonoid that exhibits antioxidant and anti-inflammatory properties. This study aimed to determine the mechanism underlying the protective effect of hesperidin on human HaCaT keratinocytes against PM_2.5-induced mitochondrial damage, cell cycle arrest, and cellular senescence. Human HaCaT keratinocytes were pre-treated with hesperidin and then treated with PM_2.5. Hesperidin attenuated PM_2.5-induced mitochondrial and DNA damage, G₀/G₁ cell cycle arrest, and SA-βGal activity, the protein levels of cell cycle regulators, and matrix metalloproteinases (MMPs). Moreover, treatment with a specific c-Jun N-terminal kinase (JNK) inhibitor, SP600125, along with hesperidin markedly restored PM_2.5-induced cell cycle arrest and cellular senescence. In addition, hesperidin significantly reduced the activation of MMPs, including MMP-1, MMP-2, and MMP-9, by inhibiting the activation of activator protein 1. In conclusion, hesperidin ameliorates PM_2.5-induced mitochondrial damage, cell cycle arrest, and cellular senescence in human HaCaT keratinocytes via the ROS/JNK pathway.

The role of ER stress and ATP/AMPK in oxidative stress meditated hepatotoxicity induced by citrinin

Citrinin, a secondary metabolite, can pose serious risks to the environment and organisms, but its hepatotoxic mechanisms are still unclear. Histopathological and ultrastructural results showed that citrinin-induced liver injury in Kunming mice, and the mechanism of citrinin-induced hepatotoxicity was studied in L02 cells. Firstly, citrinin mades L02 cell cycle arrest in G2/M phase by inhibition of cyclin B1, cyclin D1, cyclin-dependent kinases 2 (CDK2), and CDK4 expression. Secondly, citrinin inhibits proliferation and promotes apoptosis of L02 cells via disruption of mitochondria membrane potential, increase Bax/Bcl-2 ration, activation of caspase-3, 9, and enhance lactate dehydrogenase (LDH) release. Then, citrinin inhibits superoxide dismutase (SOD) activity and increases the accumulation of malondialdehyde (MDA) and reactive oxygen species (ROS), resulting oxidative damage in L02 cells; upregulates the protein expression of binding immunoglobulin protein (Bip), C/EBP homologous protein (CHOP), PKR-like ER kinase (PERK) and activating transcription factor6 (ATF6), inducing ER stress in L02 cells; increases the phosphorylation of AMP-activated protein kinase (AMPK) and decreases the content of adenosine-triphosphate (ATP), activating AMPK pathway in L02 cells. Eventually, pretreatment with NAC, an ROS inhibitor, alleviates citrinin-induced cell cycle G2/M arrest and apoptosis by inhibiting ROS-mediated ER stress; pretreatment with 4-PBA, an ER stress inhibitor, reversed ER stress and p-AMPK; pretreatment with dorsomorphin, an AMPK inhibitor, decreases citrinin-induced cell cycle G2/M arrest and apoptosis. In summary, citrinin induces cell cycle arrest and apoptosis to aggravate liver injury by activating ROS-ER stress-AMPK signaling pathway.

Citrinin Mycotoxin Contamination in Food and Feed: Impact on Agriculture, Human Health, and Detection and Management Strategies

Citrinin (CIT) is a mycotoxin produced by different species of Aspergillus, Penicillium, and Monascus. CIT can contaminate a wide range of foods and feeds at any time during the pre-harvest, harvest, and post-harvest stages. CIT can be usually found in beans, fruits, fruit and vegetable juices, herbs and spices, and dairy products, as well as red mold rice. CIT exerts nephrotoxic and genotoxic effects in both humans and animals, thereby raising concerns regarding the consumption of CIT-contaminated food and feed. Hence, to minimize the risk of CIT contamination in food and feed, understanding the incidence of CIT occurrence, its sources, and biosynthetic pathways could assist in the effective implementation of detection and mitigation measures. Therefore, this review aims to shed light on sources of CIT, its prevalence in food and feed, biosynthetic pathways, and genes involved, with a major focus on detection and management strategies to ensure the safety and security of food and feed.

Citrinin impairs pig oocyte maturation by inducing oxidative stress and apoptosis

Citrinin (CTN) is a polyketide mycotoxin produced by several strains of Penicillium, Monascus, and Aspergillus. While CTN poses various toxic effects on the female reproductive system in animals, its direct effects on germ cell development are unclear. This study aimed to evaluate the effects of increasing concentrations of CTN (0,20,40,80,100 μM) on porcine oocyte in vitro maturation. Our results indicate that CTN supplementation inhibited polar body extrusion in a dose-dependent manner. Actin and spindle assembly were also disrupted after treatment, indicating that CTN affects the cytoskeleton of porcine oocytes. Oxidative stress and apoptosis were observed under CTN treatment to explore the cause of meiotic maturation failure in porcine oocytes. The results showed that reactive oxygen species levels, cathepsin B activity, and caspase-3 activity were increased in the treated group, indicating that CTN induced oxidative stress and apoptosis. In conclusion, CTN exposure could reduce porcine oocyte maturation by affecting cytoskeletal dynamics, oxidative stress, and apoptosis.

Characterization and inhibition of four fungi producing citrinin in various culture media

PURPOSE

This study aimed to investigate the effects of different fermentation conditions (culture medium, temperature, incubation time, pH value and additive) on citrinin production by four fungi.

RESULTS

Among the culture media, potato dextrose medium had lowest citrinin production, followed by yeast sucrose medium and monosodium glutamate medium. The lowest citrinin contents were produced by Monascus anka (M. anka) in potato dextrose medium and yeast sucrose medium, Aspergillus oryzae AS3.042 (A. oryzae) produced the lowest citrinin production in monosodium glutamate medium. The optimum fermentation temperatures for citrinin production by Aspergillus niger (A. niger) and Penicillium citrinum (P. citrinum) were at 30 °C, whereas those by M. anka and A. oryzae were at 35 °C. Citrinin synthesis by four fungi were completely inhibited with a pH value of less than 5.4. By adding ethylene diamine tetraacetic acid (EDTA) or triammonium citrate into monosodium glutamate medium, citrinin production by A. oryzae and A. niger were totally inhibited. Ammonium sulfate completely inhibited citrinin production by A. oryzae, M. anka and P. citrinum, and ammonium nitrate completely inhibited citrinin production by A. oryzae.

CONCLUSIONS

These results indicated that the suitable fermentation conditions could make considerable contributions to the reduction of citrinin production. This study provided an effective way for decreasing the citrinin production.

A Study of Carry-Over and Histopathological Effects after Chronic Dietary Intake of Citrinin in Pigs, Broiler Chickens and Laying Hens

Citrinin (CIT) is a polyketide mycotoxin occurring in a variety of food and feedstuff, among which cereal grains are the most important contaminated source. Pigs and poultry are important livestock animals frequently exposed to mycotoxins, including CIT. Concerns are rising related to the toxic, and especially the potential nephrotoxic, properties of CIT. The purpose of this study was to clarify the histopathological effects on kidneys, liver, jejunum and duodenum of pigs, broiler chickens and laying hens receiving CIT contaminated feed. During 3 weeks, pigs (n = 16) were exposed to feed containing 1 mg CIT/kg feed or to control feed (n = 4), while 2 groups of broiler chickens and laying hens (n = 8 per group) received 0.1 mg CIT/kg feed (lower dose group) and 3 or 3.5 mg CIT/kg feed (higher dose group), respectively, or control feed (n = 4). CIT concentrations were quantified in plasma, kidneys, liver, muscle and eggs using a validated ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method. Kidneys, liver, duodenum and jejunum were evaluated histologically using light microscopy, while the kidneys were further examined using transmission electron microscopy (TEM). Histopathology did not reveal major abnormalities at the given contamination levels. However, a significant increase of swollen and degenerated mitochondria in renal cortical cells from all test groups were observed (p < 0.05). These observations could be related to oxidative stress, which is the major mechanism of CIT toxicity. Residues of CIT were detected in all collected tissues, except for muscle and egg white from layers in the lowest dose group, and egg white from layers in the highest dose group. CIT concentrations in plasma ranged between 0.1 (laying hens in lower dose group) and 20.8 ng/mL (pigs). In tissues, CIT concentrations ranged from 0.6 (muscle) to 20.3 µg/kg (liver) in pigs, while concentrations in chickens ranged from 0.1 (muscle) to 70.2 µg/kg (liver). Carry-over ratios from feed to edible tissues were between 0.1 and 2% in pigs, and between 0.1 and 6.9% in chickens, suggesting a low contribution of pig and poultry tissue-derived products towards the total dietary CIT intake for humans.

The protective effect of stilbenes resveratrol and pterostilbene individually and combined with mycotoxin citrinin in human adenocarcinoma HT-29 cell line in vitro

This study was focused to determine an individual and combined effect of mycotoxin citrinin (CIT) and two compounds of the stilbene family- resveratrol (RES) and his dimethyl ether analogue pterostilbene (PTE) which have many health benefits. As a model the human adenocarcinoma cell line HT-29 was used which may exhibits the properties of small intestine cells. Viability, plasma membrane integrity, lysosomal functionality, intracellular production of superoxide anions and superoxide dismutase activity were examined. The results indicate that concentrations of 50 and 100 μg/mL of the tested compounds were cytotoxic in mostly monitored parameters and probably caused apoptosis. HT-29 cells were more sensitive to PTE than to RES with a higher antioxidant effect of PTE than RES, which may be caused by its chemical structure. Both stilbenes at medium doses act as effective superoxide anions scavengers leading to reduction of oxidative stress and consequent cell damage. The nontoxic concentration of RES (25 µg/mL) protects the HT-29 cell line faced to the toxicity of CIT at 25 µg/mL by increasing viability of cells and by reducing the superoxide production induced by CIT concentrations of 12.5 µg/mL and 25 µg/mL.

Cytogenotoxic evaluation of the acetonitrile extract, citrinin and dicitrinin-A from Penicillium citrinum

Endophytic fungi are promising sources of bioactive substances; however, their secondary metabolites are toxic to plants, animals, and humans. This study aimed toevaluate the toxic, cytotoxic, mutagenic and oxidant/antioxidant activities of acetonitrile extract (AEPc), citrinin (CIT) and dicitrinin-A (DIC-A) of Penicillium citrinum. For this, the test substances at 0.5; 1.0; 1.5 and 2 μg/mLwere exposed for 24 and 48 h in Artemia salina, and 48 h in Allium cepa test systems. The oxidant/antioxidant test was evaluated in pre-, co- and post-treatment with the stressor hydrogen peroxide (H₂O₂) in Saccharomyces cerevisiae. The results suggest that the AEPc, CIT and DIC-A at 0.5; 1.0; 1.5 and 2 μg/mL showed toxicity in A. saline, with LC₅₀ (24 h) of 2.03 μg/mL, 1.71 μg/mL and 2.29 μg/mL, and LC₅₀ (48 h) of 0.51 μg/mL, 0.54 μg/mL and 0.54 μg/mL, respectively.In A. cepa, the test substances also exerted cytotoxic and mutagenic effects. The AEPc, CIT and DIC-A at lower concentrations modulated the damage induced by H₂O₂ in the proficient and mutant strains of S. cerevisiae for cytoplasmic and mitochondrial superoxide dismutase. Moreover, the AEPc at 2 μg/mL and CIT at the two highest concentrations did not affect the H₂O₂-induced DNA damage in the test strains. In conclusion, AEPc, CIT and DIC-A of P. citrinum may exert their toxic, cytotoxic and mutagenic effects in the test systems possibly through oxidative stress induction pathway.

Lovastatin in lactone and hydroxy acid forms and citrinin in red yeast rice powders analyzed by HPTLC-UV/FLD

For the analysis of pigment-rich red yeast rice products, a fast quantitative high-performance thin-layer chromatography (HPTLC) method was newly developed and validated. The active ingredient lovastatin, present in lactone (LL) and hydroxy acid forms (LH), as well as the mycotoxin citrinin were analyzed in 19 red yeast rice products, including powders, dietary supplements, and Chinese proprietary medicines (Xuezhikang and Zhibituo). The HPTLC method including sample preparation allows a high throughput of matrix-rich samples (10 min per analysis) and is highly cost-efficient (running costs of 0.5 Euro per analysis). For a fast protocol, application volumes up to 10 μL were selected although higher application volumes will lower still the LODs, which were 30 mg/kg for LL and LH as well as 4 mg/kg for citrinin. Thanks to the minimalistic sample preparation, the overall mean recovery rate was good (109.9% ± 5.9%; repeated measurements of the three analytes per fresh sample preparation at three spike levels). Repeated calibrations (five per analyte) in the red yeast rice matrix showed highly satisfying determination coefficients (≥ 0.9991; mean 0.9996). For three analytes at three concentration levels, the obtained mean intermediate precisions in red yeast rice matrix analyzed over the whole procedure including sample preparation were highly satisfying (≤ 2.6%). Citrinin was not detectable in the samples down to the given LOD of 4.0 mg/kg for the 10-μL sample volume applied. The mean content of lovastatin in 15 RYR powders was 8.7 g/kg, with a rang of 1.5-26.2 g/kg. The content of lovastatin in Zhibituo tablets and Xuezhikang capsules was determined to be 2.7 and 11.1 g/kg, respectively. The two commercially available RYR dietary supplement samples showed the highest lovastatin contents of 40.7 and 41.4 g/kg. By these figures of merit, the HPTLC method was proven to be suited for the control of such matrix-rich, fermented food. Graphical abstract.

Alternariol induced proliferation in primary mouse keratinocytes and inflammation in mouse skin is regulated via PGE2/EP2/cAMP/p-CREB signaling pathway

Alternariol (AOH) is a mycotoxin that contaminates various food stuffs as well as animal feed and may cause toxicity after consumption. However, a dermal toxic potential of AOH has not been explored so far. In the present study, skin toxicity after topical exposure of AOH and the involved mechanism/s are revealed. Single topical application of different AOH doses (12.5, 25, 50 μg/animal) caused increased bi-fold thickness as well as hyperplasia and higher production of prostaglandin E2 (PGE₂) along with cAMP in the skin demonstrating its inflammatory potential. Western blot analysis showed that exposure of AOH lead to phosphorylation of CREB and increased the expression of COX-2, cyclin D1 as well as prostanoid EP2 receptor. Further studies on primary mouse keratinocytes (PMK) revealed that very low concentrations of AOH (50-500 nM) resulted in significant PMK proliferation. Additionally, using specific antagonist or agonist of prostanoid receptors, we delineated that EP2 receptor play a key role in AOH-induced PMKs proliferation. Collectively, our findings show that AOH can lead to dermal toxicity in mice by activating the EP2/cAMP/p-CREB signaling cascade.

Fabrication of MgO nanostructures and its efficient photocatalytic, antibacterial and anticancer performance

Magnesium oxide (MgO) nanostructures were prepared using microwave-assisted (M 1) and hydrothermal (M 2) methods and characterized by XRD, SEM and FT-IR. It exhibits cubic structure with an average crystallite size of 20 nm (M 1) and 14 nm (M 2) and the lattice strain (WH plot) is 0.0017 (M 1), 0.0037 (M 2). It's spherical and rods like structures are confirmed through SEM and TEM. The vibrational stretching mode of MgO is 439 (M 1) and 449 cm^-1 (M 2). The optical bandgap is estimated as 5.93 eV (M 1) and 5.85 eV (M 2) through UV-Vis spectra. The fluorescence spectrum shows emission peaks at 414 and 437 (M 1) and 367 and 385 nm (M 2). The photodegradation studies of MgO nanostructures were assessed by monitoring the decolorization of methylene blue and Congo red dyes in aqueous solution under sunlight irradiation. The antibacterial activities of M 1 and M 2 are investigated against the gram-negative (Escherichia coli, Shigella flexneri, Salmonella typhi, Proteus mirabilis, Aeromonas hydrophila and Vibrio cholera) and gram-positive (Bacillus subtilis and Rhodococcus rhodochrous) bacteria. The zone of inhibition of 24 (M 1) and 25 mm (M 2) indicates high antibacterial activity towards the gram negative bacterium A. hydrophila. Confocal laser scanning microscopic (CLSM) analysis was utilized for understanding the variation in antibacterial activity between different orientations of MgO nanostructures. The cytotoxicity assay confirmed that the prepared nanostructures are non - toxic to normal healthy RBC's. In-vitro anticancer efficiency (IC₅₀) of MgO nanostructures against human lung cancer cell line (A549) was investigated.

Molecular signatures of cytotoxic effects in human embryonic kidney 293 cells treated with single and mixture of ochratoxin A and citrinin

Ochratoxin A (OTA) and citrinin (CTN) are important mycotoxins, which often coexist in food and feed stuff. In this study, individual and combinative cytotoxicity of OTA and CTN were tested in human embryonic kidney (HEK) 293 cells via MTT assay, and synergistic cytotoxic effects were found following co-treatment with OTA and CTN, manifested by significant accumulation of HEK293 cells in S and G2/M stages. Transcriptomic and sRNA sequencing were performed to explore molecular signatures mediating individual or combinative cytotoxicity. A total of 378 miRNAs were identified, among which 66 miRNAs targeting thousands of genes were differentially expressed in response to different treatments, and 120 differentially expressed genes (DEGs) were regulated by either individual or combinative treatments. Correlations between two representative miRNAs (hsa-miR-1-3p and hsa-miR-122-5p), and their target genes, programmed cell death 10 (PDCD10) and cyclin G1 (CCNG1), associated with apoptotic signaling and cell cycle were analyzed by luciferase assay system. Further, their expression patterns were validated by quantitative real-time PCR and western blot analysis, suggesting that both miRNA-target interactions might account for the mycotoxin-induced cell death. Taken together, these findings provide molecular evidences for synergistic cytotoxic effects of exposure to single and mixture of OTA and CTN in HEK293 cells.

iTRAQ-Based Quantitative Proteomic Analysis Reveals Changes in Metabolite Biosynthesis in Monascus purpureus in Response to a Low-Frequency Magnetic Field

Background: Low-frequency magnetic fields (LF-MFs) dampen the citrinin output by Monascus purpureus in fermentations. The influence of LF-MFs on biosynthesis by M. purpureus was evaluated at the protein level. Methods: Cultures were treated with a 1.6-mT MF from day 0 to day 2 of incubation, and secondary metabolite production was evaluated on the day 12 of incubation. All proteins were extracted from M. purpureus mycelia and subjected to isobaric tags for relative and absolute quantification (iTRAQ) labeling and subsequent liquid chromatography/mass spectrometry (LC-MS/MS) analysis on day 6 of fermentation. Results: There was no difference in biomass between the treated samples and the control. Citrinin production was 46.7% lower, and the yields of monacolin K and yellow, orange, and red pigment were 29.3%, 31.3%, 41.7%, and 40.3% higher, respectively, in the exposed samples compared to the control. Protein expression in M. purpureus under LF-MF treatment was quantified using iTRAQ technology. Of 2031 detected proteins, 205 were differentially expressed. The differentially-expressed proteins were subjected to Gene Ontology (GO) functional annotation and statistical analysis, which revealed that they mainly refer to biological metabolism, translation, antioxidant, transport and defense pathways. Among all the tagged proteins, emphasis was placed on the analysis of those involved in the synthesis of citrinin, pigment and monacolin K was emphasized. Conclusions: LF-MFs affected Monascus secondary metabolism at the protein level, and aggregate data for all the protein profiles in LF-MF-treated Monascus was obtained.

Copper Nanoparticles Show Obvious in vitro and in vivo Reproductive Toxicity via ERK Mediated Signaling Pathway in Female Mice

Copper nanoparticles (Cu-NPs) and other inorganic nanomaterials have caused increasing concern owing to be widely used. Early studies have reported that they can result in injuries to the kidney, liver and spleen of mice; cause embryonic damage; and inhibit the reproductive capacity of red worms. However, few studies have reported the toxicity of Cu-NPs on the reproductive systems of mammals. In the present work, we explored the cytotoxicity of Cu-NPs in human extravillous trophoblast cells and in the reproductive organs of mice. Cu-NPs induced ovarian and placental pathophysiology and dysfunction in mice. These nanoparticles also induced apoptosis and suppressed the proliferation of human extravillous trophoblast cells and caused cell cycle arrest at the G2/M phase in a time-and dose-dependent manner. Cu-NPs can significantly damage the mitochondrial membrane potential (MMP), which suggests that Cu-NPs can activate the mitochondria-mediated apoptosis signaling pathway. We also observed that Cu-NPs significantly inhibit the expression of BRAF, ERK, and MITF expression, all of which are important genes in the ERK signaling pathway. Our research demonstrated that Cu-NPs exert obvious reproductive toxicity in mice by disrupting the balance of sex hormones and exert cytotoxicity on human extravillous trophoblast cells, and ERK signaling and the mitochondrial apoptosis pathway made great contribution to the toxicity of Cu-NPs on female mice.

Citrinin exposure affects oocyte maturation and embryo development by inducing oxidative stress-mediated apoptosis

Citrinin is one of the mycotoxins and has been shown to have various toxic effects in animals and humans. Although previous study showed the toxic effects of citrinin on the female reproductive system, especially on oocyte maturation, however, the causes or mechanism of citrinin on oocyte quality is unclear. In present study we deeply investigated this topic. We found thatcitrinin toxin exposure inhibited mouse oocyte maturation and early embryo development. Further investigation showed that the actin distribution in oocytes and embryos was disrupted, and the reduced expression of actin nucleator ARP2 expression in the oocyte cortex further confirmed this. We also found that meiotic spindle morphology was abnormal after citrinin treatment. These results indicated that citrinin toxin exposure could disrupt cytoskeleton dynamics to affect oocyte maturation and early embryo development. We also examined the ROS level and early apoptosis marker Annexin signals, and the results showed that both levels increased, indicating that citrinin induced oxidative stress and further resulted in oocyte early apoptosis. Taken together, our results indicated that citrinin toxin exposure could reduce mouse oocyte maturation and early embryo development capability by affecting cytoskeletal dynamics, which may be due to the oxidative stress induced early apoptosis.

Differential Gene Expression Analysis of Bovine Macrophages after Exposure to the Penicillium Mycotoxins Citrinin and/or Ochratoxin A

Mycotoxins produced by fungal species commonly contaminate livestock feedstuffs, jeopardizing their health and diminishing production. Citrinin (CIT) and ochratoxin A (OTA) are mycotoxins produced by Penicillium spp. and commonly co-occur. Both CIT and OTA can modulate immune response by inhibiting cell proliferation and differentiation, altering cell metabolism, and triggering programmed cell death. The objective of this study was to determine the effects of sublethal exposure (i.e., the concentration that inhibited cell proliferation by 25% (IC₂₅)) to CIT, OTA or CIT + OTA on the bovine macrophage transcriptome. Gene expression was determined using the Affymetrix Bovine Genome Array. After 6 h of exposure to CIT, OTA or CIT + OTA, the number of differentially expressed genes (DEG), respectively, was as follows: 1471 genes (822 up-regulated, 649 down-regulated), 5094 genes (2611 up-regulated, 2483 down-regulated) and 7624 genes (3984 up-regulated, 3640 down-regulated). Of these, 179 genes (88 up-regulated, 91 down-regulated) were commonly expressed between treatments. After 24 h of exposure to CIT, OTA or CIT + OTA the number of DEG, respectively, was as follows: 3230 genes (1631 up-regulated, 1599 down-regulated), 8558 genes (4167 up-regulated, 4391 down-regulated), and 10,927 genes (6284 up-regulated, 4643 down-regulated). Of these, 770 genes (247 up-regulated, 523 down-regulated) were commonly expressed between treatments. The categorization of common biological functions and pathway analysis suggests that the IC₂₅ of both CIT and OTA, or their combination, induces cellular oxidative stress, a slowing of cell cycle progression, and apoptosis. Collectively, these effects contribute to inhibiting bovine macrophage proliferation.

A comprehensive review on biological properties of citrinin

Citrinin (CIT) is a mycotoxin which causes contamination in the food and is associated with different toxic effects. A web search on CIT has been conducted covering the timespan since 1946. The accumulated data indicate that CIT is produced by several fungal strains belonging to Penicillium, Aspergillus and Monascus genera, and is usually found together with another nephrotoxic mycotoxin, ochratoxin A. Although, it is evident that CIT exposure can exert toxic effects on the heart, liver, kidney, as well as reproductive system, the mechanism of CIT-induced toxicity remains largely elusive. It is still controversial what are the genotoxic and mutagenic effects of CIT. Until now, its toxic effect has been linked to the CIT-mediated oxidative stress and mitochondrial dysfunction in biological systems. However, the toxicity strongly depends on its concentration, route, frequency and time of exposure, as well as from the used test systems. Besides the toxic effects, CIT is also reported to possess a broad spectrum of bioactivities, including antibacterial, antifungal, and potential anticancer and neuro-protective effects in vitro. This systematic review presents the current state of CIT research with emphasis on its bioactivity profile.

Low doses of the mycotoxin citrinin protect cortical neurons against glutamate-induced excitotoxicity

Citrinin, a natural mycotoxin that is found in fermented foods, is known as a cytotoxin and nephrotoxin. Exposure to high doses of citrinin result in apoptosis; however, the effects of low doses are not fully understood. Glutamate excitotoxicity is responsible for neuronal death in acute neurological disorders including stroke, trauma and other neurodegenerative diseases. Here, we show the neuroprotective effect of low doses of citrinin against glutamate-induced excitotoxicity. We examined the effect of citrinin exposure on glutamate-induced cell death in cultured rat cortical neurons under two conditions: simultaneous treatment with citrinin 0.1 to 1,000 nM and glutamate (30 μM) for 1, 3 hr; the same simultaneous treatment for 3 hr after pretreatment with citrinin for 21 hr. Both the MTT and immunocytochemical assay showed significant neuroprotective effects at several doses and exposure times tested. All concentrations of citrinin tested showed no remarkable cell death following 14-day exposure, and no marked alterations to synapses. These data suggest that low doses of citrinin can be used as a neuroprotective agent against glutamate-induced excitotoxicity without additional harmful cellular alterations.

Role of Glutathione-S-transferases in neurological problems

INTRODUCTION

Role of Glutathione-S-transferases (GSTs) has been well explored in the cellular detoxification process, regulation of redox homeostasis and S-glutothionylation of target proteins like JNK, ASK1 etc. However, altered levels or functions of this enzyme or their subtypes have emerged in the development of several pathologies diseases such as Alzheimer's disease, Parkinson's disease, cancer and related conditions. Oxidative stress is one of the possible pathological events that contributes significantly to activation of degenerating cascades inside neuronal cells. The central nervous system is highly sensitive to oxidative stress because of low levels or capacities of antioxidant enzymes. The brain is highly metabolic in nature making it susceptible to oxidative stress. Areas covered: The present review provides a comprehensive overview of the multiple connections of GSTs within diverse neurological diseases including cancer. Furthermore, the authors have made significant efforts to discuss the regulation of different GST isoforms that have been associated with various pathological processes such as glioblastoma, Alzheimer's disease, Parkinson's disease, stroke and epilepsy. Expert opinion: Though GSTs have been one of the key areas of scientific research over the last few decades, much remains to be elucidated about their physiological functions as well as pathological involvement of GSTs and their polymorphic variants.

Different Toxicity Mechanisms for Citrinin and Ochratoxin A Revealed by Transcriptomic Analysis in Yeast

Citrinin (CIT) and ochratoxin A (OTA) are important mycotoxins, which frequently co-contaminate foodstuff. In order to assess the toxicologic threat posed by the two mycotoxins separately or in combination, their biological effects were studied here using genomic transcription profiling and specific live cell gene expression reporters in yeast cells. Both CIT and OTA cause highly transient transcriptional activation of different stress genes, which is greatly enhanced by the disruption of the multidrug exporter Pdr5. Therefore, we performed genome-wide transcription profiling experiments with the pdr5 mutant in response to acute CIT, OTA, or combined CIT/OTA exposure. We found that CIT and OTA activate divergent and largely nonoverlapping gene sets in yeast. CIT mainly caused the rapid induction of antioxidant and drug extrusion-related gene functions, while OTA mainly deregulated developmental genes related with yeast sporulation and sexual reproduction, having only a minor effect on the antioxidant response. The simultaneous exposure to CIT and OTA gave rise to a genomic response, which combined the specific features of the separated mycotoxin treatments. The application of stress-specific mutants and reporter gene fusions further confirmed that both mycotoxins have divergent biological effects in cells. Our results indicate that CIT exposure causes a strong oxidative stress, which triggers a massive transcriptional antioxidant and drug extrusion response, while OTA mainly deregulates developmental genes and only marginally induces the antioxidant defense.

Anti-Proliferative Effect of Copper Oxide Nanorods Against Human Cervical Carcinoma Cells

Metal oxide nanoparticles have been widely investigated for its use in the pharmacological field. The present study was aimed to investigate the cytotoxicity of copper oxide nanorods in human cervical carcinoma cells. The effect of copper oxide nanorods on cell viability was determined by sulforhodamine-B (SRB) assay. The fluorescence and confocal microscopy analyzes showed the cell rounding and nuclear fragmentation following exposure of copper oxide nanorods. Reactive oxygen species (ROS) was increased and could initiate membrane lipid peroxidation, which in turn regulate cytokinetic movements of cells. The messenger RNA (mRNA) expression of p53 and caspase 3 was increased, which further confirms the occurrence of apoptosis at the transcriptional level. Furthermore, caspase-3 enzyme activity was increased, which also confirms the occurrence of apoptosis in tumor cells at the translational level. Taking all our experimental results together, it may suggest that the copper oxide nanorods could be a potential anti-tumor agent to inhibit cancer cell proliferation.

Copper Ion Attenuated the Antiproliferative Activity of Di-2-pyridylhydrazone Dithiocarbamate Derivative; However, There Was a Lack of Correlation between ROS Generation and Antiproliferative Activity

The use of chelators for cancer treatment has been an alternative option. Dithiocarbamates have recently attracted considerable attention owning to their diverse biological activities; thus, the preparation of new dithiocarbamate derivatives with improved antitumor activity and selectivity as well as probing the underlying molecular mechanism are required. In this study, di-2-pyridylhydrazone dithiocarbamate S-propionic acid (DpdtpA) and its copper complex were prepared and characterized, and its antiproliferative activity was evaluated. The proliferation inhibition assay showed that DpdtpA exhibited excellent antiproliferative effect in hepatocellular carcinoma (IC₅₀ = 1.3 ± 0.3 μM for HepG2, and 2.5 ± 0.6 μM for Bel-7402). However, in the presence of copper ion, the antiproliferative activity of DpdtpA was dramatically attenuated (20–30 fold) owing to the formation of copper chelate. A preliminarily mechanistic study revealed that reactive oxygen species (ROS) generation mediated the antiproliferative activity of DpdtpA, and accordingly induced apoptosis, DNA cleavage, and autophagy. Surprisingly, the cytotoxicity of DpdtpA copper complex (DpdtpA–Cu) was also involved in ROS generation; however, a paradoxical relation between cellular ROS level and cytotoxicity was observed. Further investigation indicated that DpdtpA could induce cell cycle arrest at the S phase; however, DpdtpA–Cu lacked this effect, which explained the difference in their antiproliferative activity.

Deoxynivalenol induced mouse skin tumor initiation: Elucidation of molecular mechanisms in human HaCaT keratinocytes

Among food contaminants, mycotoxins are toxic to both human and animal health. Our prior studies suggest that Deoxynivalenol (DON), a mycotoxin, behaves as a tumor promoter by inducing edema, hyperplasia, ODC activity and activation of MAPK's in mouse skin. In this study, topical application of DON, 336 and 672 nmol significantly enhanced ROS levels, DNA damage and apoptosis with concomitant downregulation of Ki-67, cyclin D, cyclin E, cyclin A and cyclin-dependent kinases (CDK4 and CDK2) thereby resulting in tumor initiation in mouse skin. Further, the elucidation of molecular mechanisms of tumor initiation by DON (0.42-3.37 nmol/ml) in HaCaT keratinocytes, revealed (i) enhanced ROS generation with cell cycle phase arrest in G0/G1 phase, (ii) increase in levels of 8-OxoG (6-24 hr) and γH2AX protein, (iii) significant enhancement in oxidative stress marker enzymes LPO, GSH, GR with concomitant decrease in antioxidant enzymes catalase, GPx, GST, SOD and mitochondrial membrane potential after DON (1.68 nmol) treatment, (iv) suppression of Nrf2 translocation to nucleus, enhanced phosphorylation with subsequent activation ERK1/2, p38 and JNK MAPK's following DON (1.68 nmol) treatment, (v) overexpression of c-jun, c-fos proteins, upregulation of Bax along with downregulation of Bcl-2 proteins, (vi) increase in cytochrome-c, caspase-9, caspase-3 and poly ADP ribose polymerase levels leads to apoptosis. Pretreatment of superoxide dismutase, mannitol and ethanol to HaCaT cells resulted in significant reduction in ROS levels and apoptosis indicating the role of superoxide and hydroxyl radicals in DON induced apoptosis as an early event and skin tumor initiation as a late event.

Regulation of the antioxidant system in cells of the fission yeast Schizosaccharomyces pombe after combined treatment with patulin and citrinin

The effects of combined treatment with patulin (PAT) and citrinin (CTN) on Schizosaccharomyces pombe cells were investigated in acute toxicity tests. In comparison with the controls the exposure of fission yeast cells (10(7) cells ml(-1)) to PAT + CTN (250 μM each) for 1 h at a survival rate of 66.6% significantly elevated the concentration of total reactive oxygen species (ROS) via increased levels of peroxides without affecting the concentrations of superoxides or the hydroxyl radical. This treatment induced a 3.08-fold increase in the specific concentration of glutathione and elevated specific activities of catalase and glutathione S-transferase, while at the same time the activity of glutathione reductase decreased. The pattern of the ROS was the same as that induced by CTN (Máté et al., 2014), while the presence of PAT in the PAT + CTN combination treatment modified the activities of the antioxidant system (Papp et al., 2012) in comparison with the individual PAT or CTN treatment, suggesting toxin-specific regulation of glutathione and the enzymes of the antioxidant system and the possibility that the transcription factor (pap1 and atf1) -regulated processes might be influenced directly by ROS.

Hepatotoxic effect of ochratoxin A and citrinin, alone and in combination, and protective effect of vitamin E: In vitro study in HepG2 cell

Ochratoxin A (OTA) and citrinin (CTN) are the most commonly co-occurring mycotoxins in a wide variety of food and feed commodities. The major target organ of these toxins is kidney but liver could also be a target organ. The combined toxicity of these two toxins in kidney cells has been studied but not in liver cell. In this study HepG2 cells were exposed to OTA and CTN, alone and in combination, with a view to compare the molecular and cellular mechanisms underlying OTA, CTN and OTA + CTN hepatotoxicity. OTA and CTN alone as well as in combination affected the viability of HepG2 cells in a dose-dependent manner. OTA + CTN, at a dose of 20% of IC50 of each, produced effect almost similar to that produced by either of the toxins at its IC50 concentration, indicating that the two toxins in combination act synergistically. The cytotoxicity of OTA + CTN on hepatocytes is mediated by increased level of intracellular ROS followed/accompanied by DNA strand breaks and mitochondria-mediated intrinsic apoptosis. Co-treatment of vitamin E (Vit E) with OTA, CTN and OTA + CTN reduced the levels of ROS and the cytotoxicity. But the genotoxic effect of OTA and OTA + CTN was not completely alleviated by Vit E treatment whereas the DNA damage as caused by CTN when treated alone was obviated, indicating that OTA induces DNA damage directly whereas CTN induces ROS-mediated DNA damage and OTA + CTN combination induces DNA damage not exclusively relying on but influenced by ROS generation. Taken together, these findings indicate that OTA and CTN in combination affect hepatocytes at very low concentrations and, thereby, pose a potential threat to public and animal health.